1. Field of the Invention
The present invention relates to a manufacturing line for gypsum boards, and in particular to a coating spray apparatus and method of using for a manufacturing line for gypsum boards.
2. Discussion of Related Art
In a conventional gypsum board manufacturing process, a slurry of gypsum is sandwiched between two layers of facing sheets. After the gypsum core sets, the core, together with the facing sheets, is cut into board lengths. The cut boards are then sent through a dryer to substantially dry the gypsum core.
According to WO 02/12144, it is known to apply a coating to one side of the board. WO 02/058902 teaches applying a coating to a wet gypsum board prior to drying the gypsum board. In addition, U.S. Pat. No. 6,663,979 teaches applying a coating to a gypsum board either before or after drying of the board.
However, the gypsum board manufacturing line may be used for making different types of boards. Some of the boards may be coated with coating equipment as discussed above, and some boards may not be coated.